8.6. .balign[wl] abs-expr, abs-expr, abs-expr

Pad the location counter (in the current subsection) to a particular
storage boundary. The first expression (which must be absolute) is the
alignment request in bytes. For example .balign 8 advances
the location counter until it is a multiple of 8. If the location counter
is already a multiple of 8, no change is needed.

The second expression (also absolute) gives the fill value to be stored in the
padding bytes. It (and the comma) may be omitted. If it is omitted, the
padding bytes are normally zero. However, on some systems, if the section is
marked as containing code and the fill value is omitted, the space is filled
with no-op instructions.

The third expression is also absolute, and is also optional. If it is present,
it is the maximum number of bytes that should be skipped by this alignment
directive. If doing the alignment would require skipping more bytes than the
specified maximum, then the alignment is not done at all. You can omit the
fill value (the second argument) entirely by simply using two commas after the
required alignment; this can be useful if you want the alignment to be filled
with no-op instructions when appropriate.

The .balignw and .balignl directives are variants of the
.balign directive. The .balignw directive treats the fill
pattern as a two byte word value. The .balignl directives treats the
fill pattern as a four byte longword value. For example, .balignw
4,0x368d will align to a multiple of 4. If it skips two bytes, they will be
filled in with the value 0x368d (the exact placement of the bytes depends upon
the endianness of the processor). If it skips 1 or 3 bytes, the fill value is
undefined.